JEC COMPOSITES MAGAZINE - Issue #71 - March 2012 - 49

Recycling process of waste carbon fibre from various processing technologies to develop yarns, tapes and fabrics
The project set out to take virgin waste carbon fibre from various processing technologies and develop yarns, tapes and fabrics. Sigmatex developed a method that consisted in taking the manufacturing output waste from the weaving and NCF processes and separating them into a higher value waste suitable for the next process of conversion to sliver and yarn. Two separate streams of materials were created containing thermoset and thermoplastic fibres. The resultant materials and fabrics could then be manufactured into panels at both Net Composites (carbon fibre/thermoplastic route) and Umeco (carbon fibre/thermoset route). The yarn material was woven into plain and twill fabrics containing the virgin waste which was then ready for press moulding. The sliver material was fed into a consolidation process developed at Sigmatex where another material was added to the sliver to provide strength for manufacture of biaxial fabrics on an NCF machine. In common with other thermoplastic composites, the resultant materials can be moulded by simply heating above the melting temperature of the thermoplastic and press-forming between matched tools. Composite laminates made from 50% by weight recycled carbon/PET offer at least 90% of the tensile modulus and 50% of the tensile strength of an equivalent composite based on virgin fibres. There is significant market potential in existing carbon fibre applications (reduced cost compared to virgin carbon) and access to new markets/

Materials
Winner: Sigmatex Ltd. (Uk) Partnership Network: Umeco PLC (UK); Tilsatec (UK); University of Leeds (UK) Centre for Textile Technology; Net Composites (UK)

applications where virgin carbon fibre is currently too expensive (including glass fibre replacement).

Production process for lightweight structures based on sandwich structures and spraying of resins, typically fibre-reinforced polyurethane
In the context of an innovative project on lightweight construction, a diesel engine casing for a rail vehicle was manufactured for demonstration purposes. The demonstrator consisted of 8 sandwich components manufactured using a fibre spraying process. The casing fulfilled all the operational and misuse load cases listed in the product specifications. In this project, structurallyloaded components were produced for the first time using this manufacturing process. The size of the individual components and the overall dimensions of the demonstrator were also unique. The main benefits concern the weight savings in structural components for smalland medium-sized series in connection with an automated, superior to 45% compared to a reference structure, and the polyurethane system in rail vehicle construction meets the latest European CEN/TS 45545 flame and fire protection standard. The cost-efficient application of large-scale polyurethane sandwich structures in components for rail vehicles is also very attractive for this sector. From mid-2008 to nowadays, new characterization methods were developed to measure the thickness of the sandwich layer, in order to assist in designing the demonstrator and sandwich structures. The simulative imaging of the sandwich structures, and the failure predictions deduced from it, correlate closely with component performance under real-life conditions. The developed surfacing structure also ensures puncture resistance on impact of a 250 g steel ball at a speed of approx. 70 km/h.

Process
Winner: Fraunhofer Ict (Germany) Partnership Network: Bombardier Transportation GmbH (Germany); KraussMaffei Technologies GmbH; Bayer MaterialScience; DECS GmbH (Germany); Deutsches Zentrum für Luft- und Raumfahrt e.V (Germany); Stuttgart University Institute of Aircraft Design (Germany); Karlsruhe Institute of Technology (Germany)

No71 March 2012 /

jec composites magazine 49

http://www.jeccomposites.com/events/jec-asia-2012

JEC COMPOSITES MAGAZINE - Issue #71 - March 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #71 - March 2012